Wonderful! I stayed at Terachai's place for 3 weeks. The condo is exactly as described and is literally a one-minute walk to the BTS station. This is incredibly convenient and makes traveling to and from the condo really easy. There is also a 24 hour market with ATM machines and a great coffee shop nearby, again about a minute from Terachai's place.
Terachai is a great host and is very responsive. The apartment is thoughtfully stocked with everything that one might need (towels, water, and even some snacks/food), the bed is comfortable, and the entire place was really clean. The a/c is very powerful and the apartment gets cool quickly. Fast wifi and many different television channels to choose from after a long day. Also, the view from the kitchen is nice and the apartment is cheerful and bright. There is security at the front desk in the lobby, which might be important to some guests.
Terachai's place offers really great value for anyone staying in Bkk. Highly recommended!